The above referenced provisional and regular US co-pending applications, discuss the importance of both (1) lubrication and (2) protection from corrosion for valve actuator/valve stem junctions. Lubrication and protection from corrosion are important for valve actuator/valve stem junctions that are associated with valves operated in the open environment.
The referenced “open environment” typically includes industrial plants, such as water treatment plants and waste water plants. Environmental conditions are harsh at such industrial plants. Valves are expected to operate reliably over long periods of time.
The need for proper lubrication of contact areas between a valve actuator and a valve stem is discussed in the above applications, as is the necessity to otherwise protect the valve stem/valve actuator contact areas from corrosion caused by ambient water. The instant application particularly addresses this second issue. The instant application is directed to the specific problem of protecting the valve actuator/valve stem contact area and top actuator bearings and seal from corrosion caused by the condensation that can collect within a valve stem protector housing.
Valve stem protectors typically comprise long cylindrical sleeves affixed to the top of valve actuators by any one of a number of means and covering protruding portions of a valve stem. The protectors shield the valve stem and actuator joint areas from ambient atmospheric and environmental conditions, such as rain and snow and dust. They attempt to inhibit rust and corrosion of the active joints between the valve stem and actuator.
A general need to lubricate the contact area between the valve actuator and the valve stem is accepted in the industry. However, in addition, the instant inventor has discovered that condensation formed on the inside of a protective stem housing can be a significant source of, and a contributing cause to, corrosion and contamination of the valve stem/valve actuator contact area. It is important to keep condensation out of the top of the electrical actuator, where there is a seal and bearings, and out of the gear box and seal area associated therewith. Thus, notwithstanding general lubrication procedures and the presence of a stem housing, minimizing the effect of this source of corrosion and contamination provides an effective compliment to proper lubrication for maintaining an effective valve actuation system over long periods of time in harsh environmental conditions.
The instant inventor installed, in certain New York City water treatment plants, test models of the instant novel stem protector systems, prototypes that provided for the drainage of condensation from within the protector housing. The test models are yet working as designed. Engineers at NYC-DEP have taken notice of the instant inventor's solution to the condensation problem. One New York City mechanical plant and design engineer, who had taken notice of the problem and the instant inventor's solution, added the following technical reasoning, from his perspective, as to the nature of the problem. E.g.:                “At Hunts Point some people were observing that new Limitorque/Rodney-Hunt units were having extensive water build-up while new Rotork/Craft units were not, and both were outside, so some reasoned that Rotork and Craft had some solution to this problem that Limitorque and Rodney Hunt failed to solve. I know Rodney-Hunt seemed puzzled when we discussed this, and as far as I know only EIM [instant inventor] has developed a true solution to the water problem, so how could Rotork and Craft stop the water?        “After looking at this location the other day I believe I learned why Rotork and Craft lucked-out. As far as I can see the Rotork and Craft units are installed under an extensive air pipe and support truss system, but all the Rodney-Hunt gates are in the open exposed to the sky, and exposure to the open sky is the key to this.        “If you park your car outside over night you might notice dew or frost on the car. If you examine this you should notice that the parts of the car that face trees or buildings do not have dew or frost, but the parts that face the sky do, unless you are in a foggy area where everything gets covered. The reason for only some parts getting the dew is heat exchange through thermal radiation. All objects directly exchange heat by infrared thermal radiation. Like all forms of heat transfer the net exchange is proportional to the temperature difference, so a car parked outside is almost the same temperature as a nearby building or tree; therefore there is almost no heat transferred between these objects, and the solid object is at air temperature, so the water does not condense on the object. On a 70F day the clear sky temperature will be about 40F, so there will be heat lost from the car or stem cover to the sky if they have a clear and wide angle view of the sky, so while the air inside the cover may be relatively warm and hold water, the air near the stem cover gets cooled and causes condensation to form inside the cover. Meanwhile the stem covers under the air pipes have only an obstructed view of the sky at best, and they will be insulated against radiative heat loss to the sky, and they may even get radiative heating from the hot air piping.        “By the way condensation will not form on the stem, because due to a greenhouse effect the infrared radiation does not pass through the stem cover which only allows visible light to pass through it, so the stem does not thermally see the sky. The stem only thermally sees the stem cover, and even though the stem cover is cool enough to form condensation, it is not cool enough to cool the stem.        “Getting back to the Limitorque/Rodney-Hunt water problem, I do not see any breather modifications that will stop the water buildup, because these units happen to be in an unlucky spot. I think the only thing that can be done is to implement an EIM like [instant invention] fix and drain the water away from the stem.”Such confirms the utility and novelty of the instant invention.        
To the instant inventor's best knowledge, only cursory attention to date has been paid to the problem associated with condensation build up inside stem protector housings. To the extent that stem protector housings have been provided with a simple “breathing” opening in the past, the condensation problem was not solved. Furthermore, the simple “breathing” openings attracted unwanted pollution inside of the housing.
The instant inventor determined that what is needed is a draining (or wicking) system for the stem protector housing, which is more than a simple “breathing” opening. This draining (or wicking) process, from inside a protector housing to outside a protector housing, includes a condensation collection structure, directing condensation to an opening located in a lower portion of, as at the bottom of, the housing.
Such collection or drain structure could be defined by portions of the stem protection assembly and/or housing. It could be defined, at least in part, by portions of the valve actuator housing itself, either as existing in current valve actuator designs or as modified in future designs. (That is, actuator designs could be modified such that they cooperated with stem protector assemblies to help provide drainage for housing condensate.) Drains, collection structure and openings, could also be designed to retrofit existing stem protector housings.